1. Field of the Invention
The present invention relates to a process for producing thin films and optical members, and more particularly to a process for producing thin films and optical members which are free from discoloration of lens and exhibit a good antistatic property and a good water repellency.
2. Description of the Prior Art
There are conventionally known optical members constituted of a plastic substrate and an anti-reflection film which is formed on the substrate by vapor-depositing an inorganic substance, etc. Such optical members are excellent in anti-reflection property and scratch resistance. However, the optical members having such an anti-reflection film are insufficient in antistatic property the substrate is plastic. As a method to solve this problem, it is known to successively form a hard coat layer and an antistatic hard coat layer on the plastic substrate (JP 2002-329598A). It is further known that an optical thin film made of a conductive metal oxide obtained by reacting a metal with an unfixed amount of oxygen is introduced into anti-reflection films to impart the antistatic property to the optical member (EP 0834092A). In addition, there is known a process for producing a thin film in which a thin film-forming material composed of a water-repellent material added with a conductive substance such as a carbon paste is evaporated by an electron gun (JP 11-310869A).
However, the antistatic hard coat layer described in JP 2002-329598A, etc., is satisfactory in the antistatic effect, but absorbs visible light largely and discolors lens. The optical member described in EP 0834092A, etc., is satisfactory in the antistatic effect, but its surface is poor in the scratch resistance. Further, in the process for producing a thin film as described in JP 11-310869A, although a water-repellent film is stably produced using an electron gun because the raw water-repellent material contains a conductive substance, the antistatic effect is insufficient. If the power of the electron gun for evaporation of the thin film-forming material is increased to impart the antistatic effect, the antistatic effect is made uneven over the surface of lens. Thus, the process is still unsatisfactory for the antistatic effect of the thin film.